package org.apache.lucene.index;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;

import java.util.Map;

/** This is a DocFieldConsumer that inverts each field,
 *  separately, from a Document, and accepts a
 *  InvertedTermsConsumer to process those terms. */

final class DocInverter extends DocFieldConsumer {

    final InvertedDocConsumer consumer;
    final InvertedDocEndConsumer endConsumer;

    public DocInverter(InvertedDocConsumer consumer, InvertedDocEndConsumer endConsumer) {
        this.consumer = consumer;
        this.endConsumer = endConsumer;
    }

    @Override
    void setFieldInfos(FieldInfos fieldInfos) {
        super.setFieldInfos(fieldInfos);
        consumer.setFieldInfos(fieldInfos);
        endConsumer.setFieldInfos(fieldInfos);
    }

    @Override
    void flush(Map<DocFieldConsumerPerThread, Collection<DocFieldConsumerPerField>> threadsAndFields, SegmentWriteState state) throws IOException {

        Map<InvertedDocConsumerPerThread, Collection<InvertedDocConsumerPerField>> childThreadsAndFields = new HashMap<InvertedDocConsumerPerThread, Collection<InvertedDocConsumerPerField>>();
        Map<InvertedDocEndConsumerPerThread, Collection<InvertedDocEndConsumerPerField>> endChildThreadsAndFields = new HashMap<InvertedDocEndConsumerPerThread, Collection<InvertedDocEndConsumerPerField>>();

        for (Map.Entry<DocFieldConsumerPerThread, Collection<DocFieldConsumerPerField>> entry : threadsAndFields.entrySet()) {
            DocInverterPerThread perThread = (DocInverterPerThread) entry.getKey();

            Collection<InvertedDocConsumerPerField> childFields = new HashSet<InvertedDocConsumerPerField>();
            Collection<InvertedDocEndConsumerPerField> endChildFields = new HashSet<InvertedDocEndConsumerPerField>();
            for (final DocFieldConsumerPerField field : entry.getValue()) {
                DocInverterPerField perField = (DocInverterPerField) field;
                childFields.add(perField.consumer);
                endChildFields.add(perField.endConsumer);
            }

            childThreadsAndFields.put(perThread.consumer, childFields);
            endChildThreadsAndFields.put(perThread.endConsumer, endChildFields);
        }

        consumer.flush(childThreadsAndFields, state);
        endConsumer.flush(endChildThreadsAndFields, state);
    }

    @Override
    void abort() {
        try {
            consumer.abort();
        } finally {
            endConsumer.abort();
        }
    }

    @Override
    public boolean freeRAM() {
        return consumer.freeRAM();
    }

    @Override
    public DocFieldConsumerPerThread addThread(DocFieldProcessorPerThread docFieldProcessorPerThread) {
        return new DocInverterPerThread(docFieldProcessorPerThread, this);
    }
}
